The 1983 Jasper engine is not compatible with the 1999 Wrangler. The 1983 Jasper engine is a 2.5L AMC inline-6 engine, while the 1999 Wrangler uses a 4.0L inline-6 engine. The two engines have different bolt patterns, so the 1983 Jasper engine cannot be easily swapped into the 1999 Wrangler.